so get this

as soon as sammy said “i do” to buttfucking and getting buttfucked on the regular, dean dusted his hands of any other hangers-on. but they haven't had the talk about it yet. dean ignores the fact the idea of sam having sex with anyone else makes him physically nauseous.

so he’s quite surprised when he fumbles around for a condom one night and sam shakes his head, bangs sticking to his forehead and fumbles it out of dean’s hand.

“no,” he pants, “in me, you have to come inside me dean, please. wanna feel you leaking out for hours.”

and well. fuck. dean can’t say no to that.

when it’s his turn in a few days, he rolls away from sam’s mouth and has to try to focus through sam’s open mouthed kisses and bites to his shoulder blades as he fumbles in his nightstand for a condom.

sam makes an honest to god whine when he sees it, and laces his fingers with dean, keeping dean from opening it up.

“please, dean,” he murmurs, kissing dean with enough tongue to make dean forget his own name, “wanna come inside you, don't you wanna feel me?" and somehow dean gets distracted and the next thing he knows, sam is staring intently at dean's hole, pushing his come back in with strong, overwhelming fingers.

it becomes a routine. dean'll fumble around for a condom or pull one out of his wallet or yank open the glovebox for them and sam's big clever fingers will slide it out of dean's palm and drop it to the floor or the sheets or the asphalt.

and dean can't really find it in him to complain because he's having the best sex of his life on a daily basis. sam barely lets him go fifteen hours without bending him over or pulling him down.

one day, sam jumps on dean as soon as they light a warehouse full of vampires on fire, pushing him up against the impala and fumbling wildly for dean’s belt. when sam starts rubbing his fingers down the back of dean’s sweaty day-three boxers, dean smacks at his hands and warns “hey man i haven’t had time to clean today” because dean doesn’t care if he is fucking his brother—saying i didn’t douche is embarrassing as fuck.

sam, if anything, kisses dean harder, takes dean’s wallet out of his back pocket, palms the lube and leaves the condom as he drops dean's wallet onto the ground.

dean, who sam yells at if he doesn't wash his hands after using the urinal, balks. until, well, he's distracted. you understand.

dean wises up one day after he hauls his creaky joints out of bed to get sam a washcloth—he’s the picture of chivalry despite his brain being drained out through his dick, thank you very much—and comes back to find sam rubbing dean’s come into the inside of his thigh like a fancy lotion.

a lightbulb. dean’s little brother might be a fan of dirty messy possessive smelly sex. huh.